Reprinted from the March issue of South Shore Senior News
Quincy – Even with the recent emphasis on exercise, the United States Public Health Service informs us that approximately 90 percent of Americans are essentially sedentary. In fact, most do so little physical activity they could almost be reclassified as statues. Although two of every three adults is presently following a low-calorie diet plan, only one of every 20 adults (and only one in 40 older adults) is performing regular exercise. While dieting is effective for reducing bodyweight, low-calorie eating plans result in muscle loss and metabolic slow-down which are undesirable consequences, especially for older adults.
To maintain muscle tissue and metabolic function, diet programs should be accompanied by exercise programs. Strength training is most importance because it actually increases muscle tissue and resting metabolic rate, which concurrently improves physical fitness and enhances fat loss.
The other type of exercise that should be performed for weight loss and health benefits is aerobic training. Endurance activities such as walking, jogging, cycling, stepping, and rowing burn lots of calories and provide cardiovascular conditioning in the process. Regular aerobic exercise strengthens your heart muscle, expands your capillary beds, and makes your blood a better oxygen transportation system, all of which are highly desirable for older adults.
Most people approach endurance exercise in the traditional manner, beginning with about 5 minutes of low-effort warm-up, followed by 20 to 30 minutes of moderate-effort continuous movement, and concluding with about 5 minutes of low-effort cool-down. This is an excellent training model with one exception. Performing the same type of exercise movements for relatively long training durations can lead to physiological problems, such as overuse injuries, and psychological concerns, such as boredom/burnout.
Older adults, in particular, should consider a cross-training program for increasing the health/fitness benefits and for reducing the injury risks associated with endurance exercise. Cross-training is easily accommodated at most fitness facilities due to the wide variety of aerobic equipment readily available (e.g. upright cycles, recumbent cycles, treadmills, stepping machines, stair climbing machines, elliptical trainers, rowing machines, walking tracks and swimming pools). Even home gyms can be outfitted at a reasonable cost to enable more varied aerobic activity (e.g. cycle, stepper, rower, etc.).
The two equally important objectives of a cross-training workout are: (1) to provide 20 to 30 minutes of more or less continuous endurance training for effective cardiovascular conditioning; and (2) to use two or more modes of aerobic exercise to emphasis different muscle groups for reduced risk of overuse injuries. For example, instead of 30 minutes walking on the treadmill you may substitute 10 minutes of treadmill walking, 10 minutes of upright cycling, and 10 minutes of rowing. This cross-training workout provides 30 minutes of cardiovascular exercise but emphasizes a variety of major muscle groups. Physiologically it enables you to train harder due to less muscle fatigue, with less likelihood of experiencing overuse injuries. Psychologically, it offers a more interesting workout with periodic changes in movement patterns and motor skills.
Consider the following aerobic activities that may be interchanged during your endurance training sessions, noting the major muscular emphasis of each exercise.
Upright cycling supports your bodyweight and puts more stress on your front thigh (quadriceps) muscles.
Recumbent cycling also supports your bodyweight, but places emphasis on your rear thigh (hamstrings) and hip (gluteal) muscles.
Treadmill walking/running, which uses your bodyweight resistance, places more emphasis on your rear thigh (hamstrings) muscles at slower speeds and more emphasis on your front thigh (quadriceps) muscles at faster speeds.
Stepping and stair climbing both use your bodyweight resistance and put more stress your front thigh (quadriceps) and lower leg (calf) muscles.
Elliptical training machines use your bodyweight resistance and produce a movement pattern that resembles a combination of running, cycling and stepping, which places more equal emphasis on all of the lower body muscles.
Rowing machines involve both external resistance and body movement. Unlike the other endurance exercises, rowing involves both your upper body and lower body muscles, with greatest stress on the pushing muscles of the legs (front thighs, rear thighs and buttocks) and the pulling muscles of the torso/arms (upper back, lower back, biceps).
Swimming is similar to rowing in that you use both your upper body and lower body muscles, with emphasis on those that pull your body through the water (chest, upper back and arms). Of course rowing and swimming are excellent cross-training activities when integrated with leg emphasis exercises such as cycling, running and stepping.
There is no specific pattern of cross-training combinations and no particular time limit for each exercise segment. Choose the activities that you like best and try a variety of match-ups. For example, you could do two different activities for 12 minutes each or four different exercises at 6 minutes each. After a few experimental sessions you should develop a personalized cross-training program that is perfect for you.
About the Authors
Wayne L. Westcott, Ph.D., teaches exercise science at Quincy College and consults for the South Shore YMCA. He has written 28 books on strength training and physical fitness. Rita La Rosa Loud, B.S., directs the Community Health and Fitness Center at Quincy College.